Manufacture of hydraulic cement.



UNITED STATES uric CHAR-LES JOHN POTTER, OF WILLINGTON QUAY, ENGLAND.

MANUFACTURE OF HYDRAULIC CEMENT.

Specification of Letters Batent.

Patented April 6, 1909.

Application filed. November 12, 1 908. Serial No. 462,197

Great Britain, residing at Tyne Cement YVorks, VVillington Quay, in the county of Yorthnmberland, England, have invented new and useful Improvements in the Manufacture of Hydraulic Cement, of which the following is a specification.

The object of this invention is to obtain a white hydraulic cement. For this purpose the presence of iron in the ingredlents is avoided, they are burned with fuel free from iron and the clinker is cooled in a re ducing atmosphere.

Preferably an intimate mixture of chalk, china clay and finely ground flint are burnedf preferably in a rotary kiln at a high temperature with a fuel free from iron such as tar, as or oil. The clinker is then cooled in a reducing atmosphere such as coal gas.

In place of the above mentioned materials QtlIQI' fOIDIS of calcareous matter, clay and silica may be employed provlded they are almost free from lIOIl.

varied considerably but the mixture should contain from 60 to 70 percent. of lime, 3 to '8 per cent. of alumina and 18 to 25 per cent. of silica and not more and preferablyless than per cent. of iron.

\Vhat I claim is 1. In the manufacture of cement cooling the clinker in a reducing atmosphere.

phere.

CHARLES JOHN POTTER. \Vitnesses:

JAMES BROWN,

JNO. D. CAR? 2. The manufacture of cement by burning L The proportions of the materials may be 

